Presently disclosed is a rear suspension and drive enclosure for a ridden motorized vehicle. The presently disclosed rear suspension and drive enclosure may be used with any ridden motorized vehicle having a driven axle pivotally attached to the frame of the motorized vehicle, the driven axle operably connected to a motor power source. Such ridden motorized vehicles may include motor scooters, motorcycles, all-terrain-vehicles, tricycles, snowmobiles, and lawn tractors.
Ridden motorized vehicles, such as those disclosed herein, generally comprise a frame, a power system, and at least one drive wheel. The at least one wheel may provide traction with the ground directly, or may be part of a track system such as with a snowmobile. The power from the power system must be transferred to one of the wheels, usually the rear wheel, to propel to the vehicle. The power from the power system is usually transferred to the rear wheel through a swingarm, or drive enclosure, disposed between the frame of the motorized vehicle and the rear wheel. A swingarm is used to firmly hold the axle, of the driven wheel, a fixed distance laterally from the frame while allowing the rear axle to pivot upwardly and downwardly to allow the suspension to absorb bumps and vibrations from the ground. Also the drive linkage assembly, whether a drive shaft, chain, or belt is disposed along the swingarm, providing power to the rear wheel.
Use of an enclosed drive chain or belt between the motor assembly and the rear wheel is known for use with ridden vehicles such as motorized scooters, motorcycles, all-terrain-vehicles, and snowmobiles. In most cases this includes a fixed multi-piece chain and rear sprocket housing that is mounted to the rear suspension, an enclosure for the motor sprocket which is affixed to the motor, and flexible enclosure sections which connect the upper and lower sections of the two fixed enclosures. This type of system is costly, heavy, and complex to manufacture and maintain. In scooters it is also common to have a drive system wherein the motor is attached to the rear suspension and drives the rear wheel via a gear drive, a drive shaft, or a mixture of gears and chains. Such designs described, for example, by Japanese Patent Application Publication JP 2010-228627 are complex, and the motion of the motor with the suspension increases unsprung weight to the detriment of ride quality.
Unsprung weight is the mass of every component on a ridden vehicle not supported by the suspension. Such components may include the wheels, brake systems, axel, and suspension system. In systems such as those described by JP 2010-228627 this also includes the motor and the gear system. A ridden vehicle having a lighter unsprung weight will have unsprung components moving more readily with the road bumps and irregularities, maintaining the traction between the road and the wheel, and therefore, provide a more uniform grip and improved performance. A ridden vehicle having a heavier unsprung weight will have unsprung components which will absorb less of the bumps and irregularities in the road and, therefore, vibrations will be transmitted to the rest of the vehicle, the rider, and passengers. For the same reason road noise will increase with vehicles having a heavier unsprung weight as well. Therefore, there is presently a need for a ridden motorized vehicle, such as a motor scooter, motorcycle, ATV, tricycle, snowmobile, or lawn tractor, having a lightweight rear suspension and drive enclosure system.
Further, systems of the prior art include motor scooters and motorcycles having a swingarm type rear suspension system, pivoting on an axis shaft mounted to the frame behind the engine, such that the output shaft of the engine is not aligned with the pivot point of the drive enclosure or swingarm, and include a chain drive enclosure in the swingarm. These systems require at least two chains and a double intermediary sprocket on the swingarm pivot axis, providing a system which is complex and difficult to manufacture and service. The distance between the swingarm pivot point and the rear wheel axle remains constant during operation of the motor vehicle. A ridden vehicle having a swingarm or drive enclosure pivot point not aligned with the output shaft of the motor assembly is a vehicle having a rear wheel axle having a variable distance from the output shaft of the motor assembly while the rear wheel pivots upwardly and downwardly about the swingarm pivot point. A variable distance between the rear wheel axle and the motor assembly output shaft prevents a drive chain or belt having a fixed length to directly connect the rear wheel axle with the motor assembly output shaft. Some prior art systems have a sprocket on the output shaft of the motor assembly and a final sprocket mounted on the rear wheel concentric with the axle which allows for loosening and tightening of the chain during suspension movement, caused by the variation in distance between the engine and wheel sprockets as the suspension moves, and, in turn, causing noise, wear, and imprecise drive delivery. To overcome this problem other prior art systems have a double intermediary sprocket at the swingarm pivot point, and two chains or drive belts, one between the sprocket on the output shaft of the motor assembly and the double intermediary sprocket at the swingarm pivot point, and a second between the double intermediary sprocket at the swingarm pivot point and a sprocket on the rear wheel axle. Such prior art systems have many components comprised within the drive train of the motorized vehicles and are, therefore, complex to manufacture, install, and maintain.
There is presently a need for a drive system in ridden vehicles which provides both rear suspension with an enclosed drive transfer system, such as a drive shaft, belt, or chain, while reducing the unsprung weight of the system. Also, there is presently a need for a lightweight rear suspension and drive enclosure system for a ridden motorized vehicle which has fewer parts, to reduce the cost and complexity of manufacturing, installation and maintenance of such systems. Presently disclosed is a simple two piece enclosure wherein the drive transfer system is totally enclosed, has integrated chain tensioner, has one drive transfer system, such as a drive shaft, chain, or belt between a motor assembly output shaft and rear wheel axle, has lower unsprung weight, and provides easy service access to the drive transfer system.
Presently disclosed is a ridden motorized vehicle having a drive enclosure disposed between the frame and the rear wheel. The ridden vehicle having a frame, a motor assembly attached to the frame, and the motor assembly having an output shaft. Such a motor assembly may comprise any type of motor, for example, an electric motor or an internal combustion engine. The output shaft of the motor assembly may be adapted to directly or indirectly transfer the power from the drive assembly to a desired location at least one drive wheel. In some embodiments, the motor assembly may comprise a motor, as previously discussed, and together with a gear system or gear box operably connected to the motor, the gear system adapted to change the speed of the output shaft from the motor assembly. The motor and gear system may be arranged as desired. In some embodiments, the gear system may be aligned with the output shaft of the motor, such that the motor and gear system, included as part of the motor assembly, are positioned side-by-side widthwise in the vehicle. In other embodiments, the motor and gear system included as part of the motor assembly may be positioned lengthwise in the vehicle, such that the gear system is next to, either behind or in front of, the motor, and operably connected to the motor, the gear system having an output shaft, being the output shaft of the motor assembly.
The drive enclosure of the ridden vehicle has a first end and a second end. The drive enclosure adapted to allow the rear wheel to pivot upwardly and downwardly relative to the main chassis frame, with the first end pivotally attached to the frame, the attachment point aligned with the output shaft of the motor assembly, and the second end having a rear wheel attached. The ridden vehicle may have a sprocket attached to the output shaft of the motor assembly at the first end of the drive enclosure and a sprocket attached to the rear wheel axle at the second end of the drive enclosure, with a chain or belt disposed around and between the two sprockets providing drive from the motor assembly to the rear wheel. The ridden vehicle may have a shock absorber disposed between the drive enclosure and the main chassis frame providing shock resistance for the ridden vehicle, about the first end pivoting on the frame, while being ridden over uneven terrain.
In some embodiments, the drive enclosure may comprise an inner drive enclosure section and an outer drive enclosure section fixed to the inner drive enclosure section by fasteners to provide a monocoque structural drive enclosure capable of withstanding the torsional forces exerted by the weight and motion of the vehicle as it is ridden. The inner drive enclosure section being inward along the longitudinal axis of the motor vehicle, i.e. adjacent the rear wheel, the outer drive enclosure attached to the inner drive enclosure being outward along the longitudinal axis of the ridden motor vehicle relative to the inner drive enclosure, i.e. on the side of the inner drive enclosure opposite the rear wheel. Such a configuration forms a monocoque structure. The monocoque structure of embodiments of the drive enclosure provides a drive enclosure adapted to support the structural loads and torsions exerted by the ridden vehicle during operation, by using the drive enclosure's external skin, as opposed to an internal frame or truss.
Such a monocoque structural drive enclosure provides a drive enclosure with fewer parts compared to prior art drive enclosures. The presently disclosed monocoque structural drive enclosure provides for reduced cost of manufacture, installation and maintenance, as well as reduced complexity of manufacture, installation and maintenance. The presently disclosed monocoque structural drive enclosure also provides for reduced unsprung weight of the ridden vehicle, thereby improving ride quality and reducing road noise. Also, the presently disclosed ridden vehicle, having a drive enclosure with a pivot point aligned with the motor assembly output shaft, provides a vehicle providing a single drive chain or belt between the sprocket on the motor assembly output shaft and the sprocket on the rear wheel axle while maintaining the distance between the motor assembly output shaft and the rear wheel axle, as opposed to a dual drive chain or belt system of the prior art. Therefore, a ridden vehicle of the presently disclosed design provides for reduced complexity of manufacture, installation and maintenance, as well as reduced cost for all three phases.
In some embodiments, the ridden vehicle may be a motor scooter having a motor assembly disposed on the main chassis frame, while also providing a flat board, step-through construction. This embodiment provides a motor scooter with reduced unsprung weight while also providing the step-through convenience of traditional motor scooters, which traditionally have their motor assembly disposed on the rear wheel axle. This easily maintains the attraction of the motor scooter to both men and women alike, while greatly reducing unsprung weight with the motor assembly attached to the frame of the motor scooter instead of the rear wheel axle. The greatly reduced unsprung weight provides a motor scooter with an improved ride quality and reduced road noise. In some embodiments, the ridden vehicle may be an electric scooter or a hybrid scooter.
In some embodiments, the monocoque structural drive enclosure is disposed on one side of the motorized vehicle, such as a motor scooter, motorcycle, ATV, tricycle, snowmobile, or lawn tractor, providing for easy access and maintenance to the rear wheel, allowing the rear wheel to be removed without disassembling the drive enclosure. In other embodiments, the presently disclosed monocoque structural drive enclosure may be assembled on both sides of the vehicle, having a dual drive chain or belt, providing for increased power to be transmitted between the motor assembly and the rear wheel. Furthermore, the motor assembly, as discussed above, may have an integrated or attached gear system disposed between the motor shaft and the output sprocket at the first end of the drive enclosure, the output shaft for the gear system aligned with the pivot point of the drive enclosure at the first end of the drive enclosure.
Also disclosed is a ridden vehicle comprising a frame, at least one motor assembly attached to the frame, and a motor assembly having an output shaft. The motor assembly may be attached to a motor assembly mount portion, removable from the frame. Such a configuration provides for a more simple installation and manufacturing system for assembling the ridden vehicle. The ridden vehicle may also have a drive enclosure having a first end and a second end, the first end having a frame connection point aligned with the output shaft of the motor assembly, and the second end having a wheel connection point, the drive enclosure adapted to pivot about the frame connection point. The ridden vehicle further comprises a wheel connected to the wheel connection point at the second end of the drive enclosure and a linkage apparatus disposed between the output shaft of the motor assembly and the wheel connected at the second end of the drive enclosure, the linkage apparatus adapted to transfer power from the output shaft of the motor assembly to the drive wheel. The linkage apparatus between the output shaft of the motor and the wheel may be a drive shaft, a chain, or a belt.
The drive enclosure of the presently disclosed ridden vehicle may comprise a first part and a second part, the first part positioned inwardly of the vehicle, adjacent the rear wheel, the second part positioned outwardly and fastened to the first part. Such embodiments of the drive enclosure may provide a monocoque drive enclosure.
The motor assembly comprises a motor, or alternatively a motor and at least one gear. The motor may be an internal combustion engine or an electric motor or a combination thereof. The drive enclosure may further comprise a tensioner mounted in the drive enclosure and adapted to exert a tension force to the linkage apparatus. A shock absorber and/or spring, may be disposed between the drive enclosure and the frame, to provide shock absorption when the ridden vehicle is in operation.
The presently disclosed ridden vehicle may further comprise at least one first sprocket attached to the output shaft of the motor assembly, and at least one second sprocket attached to the rear wheel axle, the linkage apparatus disposed between the first sprocket and the second sprocket.
In some embodiments, the ridden vehicle may comprise the drive enclosure disposed between the frame and the rear wheel on a single side of a vehicle. In other embodiments, the ridden vehicle may further comprise at least two drive enclosures, each drive enclosure disposed on opposing sides of the vehicle, each drive enclosure having a first end and a second end, the first end of each drive enclosure having a frame connection point aligned with the output shaft of the motor assembly, and the second end of each drive enclosure having a wheel connection point, the at least two drive enclosures adapted to pivot about the frame connection point. In embodiments of the ridden vehicle having at least two drive enclosures, the frame connection point of each drive enclosure may be adapted to attach to the frame. Where each drive enclosure is attached to the frame on opposite sides of the frame, or alternatively, each drive enclosure is attached to the frame on the same side.
Also disclosed is a drive enclosure for a ridden vehicle, comprising an inner drive enclosure disposed between a vehicle frame and a rear wheel of a vehicle, the inner drive enclosure having a first end and a second end, the first end having a frame connection point, and the second end having a wheel connection point, the inner drive enclosure adapted to pivot about the frame connection point aligned with the output shaft of a vehicle motor assembly; and an outer drive enclosure fastened to the inner drive enclosure. In some embodiments the outer drive enclosure comprises a first end and a second end, the first end having a frame connection point, and the second end having a wheel connection point, the inner drive enclosure adapted to pivot about the frame connection point aligned with a ridden vehicle motor assembly output shaft. Additionally, or in the alternative, the inner drive enclosure and outer drive enclosure form a monocoque drive enclosure.
The scope and content of the presently disclosed ridden vehicle, as discussed above, may also be augmented by the following description of the drawings. The drawings depict a two-wheeled motor scooter but the invention herein described is applicable to all forms of ridden motorized vehicles including, but not limited to, motor cycles, motor scooters, all-terrain vehicle, snow mobiles, tricycles, or lawn tractors.